Bounds on compressed voice channel capacity

The voice channels present in cellular communication networks provide reliable, widespread and high priority communication mediums. Using these voice channels as a bearer for data transmission allows to deliver high Quality of Service data. But voice channels include vocoders that hinder the data flow by compressing the waveforms prior to transmission. Calculating vocoder channel capacity remains a challenging problem since no analytical model has been proposed for the vocoder channel so far. In this research, simplified models for the vocoder channel are proposed and bounds on vocoder channel capacity are derived based on them. In common cellular networks, the vocoder compression rate is adjusted adaptively according to the network´s traffic conditions which further complicates calculating an overall capacity for the voice channel. In this research, the Gilbert-Elliot channel model is applied to the cellular voice channel to enable the study of the effect of adaptive vocoder rate adjustment on overall voice channel capacity. Modeling the voice channel and calculating its capacity provides reference bounds for comparison with any newly proposed communication scheme over this channel.